BACKGROUND: Helminth infections have proven recalcitrant to control by chemotherapy in many parts of Southeast Asia and indeed farther afield. This study isolates and examines the influence of different aspects of the physical and social environment, and uneven intervention effort contributing to the pathogenic landscape of human Opisthorchis viverrini infections. METHODOLOGY: A cross-sectional survey, involving 632 participants, was conducted in four villages in northeast Thailand to examine the impact on prevalence and parasite burden of the reservoir dam environment, socio-economic, demographic, and behavioral factors, and health center intervention efforts...

A large body of evidence suggests that dietary supplementation with omega-3 fatty acids may ameliorate depressed mood. The magnitude of the effect varies between studies, however, ranging from none at all to being of clinical significance. Given that substantial comorbidity occurs between mood and anxiety disorders, suggesting that they have one or more pathophysiological mechanisms in common, we hypothesized that omega-3 fatty acids may be acting primarily to reduce anxiety rather than depression per se, a possibility which could underlie their variable effects on mood...

Motivation can be characterized as a series of cost-benefit valuations, in which we weigh the amount of effort we are willing to expend (the cost of an action) in return for particular rewards (its benefits). Human motivation has traditionally been measured with self-report and questionnaire-based tools, but an inherent limitation of these methods is that they are unable to provide a mechanistic explanation of the processes underlying motivated behavior. A major goal of current research is to quantify motivation objectively with effort-based decision-making paradigms, by drawing on a rich literature from nonhuman animals...

Motivation in performance is often measured via competitions. Winning a competition has been found to increase the motivation to perform in subsequent competitions. One potential neurobiological mechanism that regulates the motivation to compete involves sex hormones, such as the steroids testosterone and estradiol. A wealth of studies in both nonhuman animals and humans have shown that a rise in testosterone levels before and after winning a competition enhances the motivation to compete. There is strong evidence for acute behavioral effects in response to steroid hormones...

Motivation is a complex neurobiological process that initiates, directs, and maintains goal-oriented behavior. Although distinct components of motivated behavior are difficult to investigate, appetitive and consummatory phases of motivation are experimentally separable. Different neurotransmitter systems, particularly the mesolimbic dopaminergic system, have been associated with food motivation. Over the last two decades, however, research focusing on the role of opioid signaling has been particularly growing in this area...

The Siphonaptera are parasitic insects of endothermic animals and Ctenocephalides felis and Pulex irritans are important parasites of dogs. This study evaluated the effect of hair coat length and time of year on the population size of C. felis and P. irritans in naturally infested dogs. Fleas were collected from 14 dogs on a monthly basis for a year (February 2015 to January 2016) at a rural property in Bagé, Rio Grande do Sul, Brazil. The dogs were divided into two groups based on hair coat length: short coat (coat length < 5...

Optogenetics holds great promise for both the dissection of neural circuits and the evaluation of theories centered on the temporal organizing properties of oscillations that underpin cognition. To date, no studies have examined the efficacy of optogenetic stimulation for altering hippocampal oscillations in freely moving wild-type rats, or how these alterations would affect performance on behavioral tasks. Here, we used an AAV virus to express ChR2 in the medial septum (MS) of wild-type rats, and optically stimulated septal neurons at 6 Hz and 30 Hz...

Any animal, human or non-human, lives in a world where there are others like itself. Individuals' behaviors are thus inevitably influenced by others, and cognition is no exception. Long acknowledged in psychology, social modulations of cognition have been neglected in cognitive neuroscience. Yet, infusing this classic topic in psychology with brain science methodologies could yield valuable educational insights. In recent studies, we used a non-human primate model, the rhesus macaque, to identify social influences representing ancient biases rooted in evolution, and neuroimaging to shed light on underlying mechanisms...

The rodent tasks with food rewards are useful methods to evaluate memory functions, including hole-board and corridor tests. The AMBITUS system (a square corridor with several food rewards), as a combination of these tests, was developed for the investigation of a variety of parameters associated with exploration and cognitive performance in rodents. Experiments were performed to characterize these behaviors in healthy rats and a new "schizophrenia-like" rat substrain with impaired learning ability to reveal the reliability in tests related to these functions...

Traumatic brain injury (TBI) is a major public health problem with long-term neurobehavioral sequela. The evidences have revealed that TBI is a risk factor for later development of neurodegenerative disease and both the single and repetitive brain injury can lead to the neurodegeneration. But whether the effects of accumulation play an important role in the neurodegenerative disease is still unknown. We utilized the Sprague Dawley (SD) rats to develop the animal models of repetitive mild TBI and single mild TBI in order to detect the neurobehavioral changes...

INTRODUCTION: The use of forced-swim, rat-validated cognition tests in mouse models of Traumatic Brain Injury (TBI) raises methodological concerns; such models are vulnerable to a number of confounding factors including impaired motor function and stress-induced non-compliance (failure to swim). This study evaluated the ability of a Radial Water Tread (RWT) maze, designed specifically for mice, that requires no swimming to distinguish mice with controlled cortical impact (CCI) induced TBI and Sham controls...

Sugars are important energy sources, but high sugar intake poses a metabolic challenge and leads to diseases. Drosophila melanogaster is a generalist fruit breeder that encounters high levels of dietary sugars in its natural habitat. Consequently, Drosophila displays adaptive responses to dietary sugars, including highly conserved and unique metabolic adaptations not described in mammals. Carbohydrate homeostasis is maintained by a network comprising intracellular energy sensors, transcriptional regulators, and hormonal and neuronal mechanisms that together coordinate animal behavior, gut function, and metabolic flux...

BACKGROUND: Adolescence is characterized by major neurobiological changes, and the effects of some psychoactive drugs seem to differ between adolescents and adults. Bupropion, an antidepressant that is also used to treat nicotine addiction, induces behavioral actions in both adolescent and adult rodents. However, the effects of this drug on spatial ability have not been compared in animals at different stages of their development. The present study was conducted to assess the effects of bupropion on spatial learning and memory in adolescent and adult mice...

In this study, we developed a novel unfixed-type experimental system that we call a '3-DOF servosphere.' This system comprises one sphere and three omniwheels that support the sphere. The measurement method is very simple. An experimental animal is placed on top of the sphere. The position and heading angle of the animal are observed by using a high-speed camera installed above the sphere. Because the system can rotate the sphere with three degrees of freedom (DOFs) independently, the position and heading angle at the origin can be maintained without fixing the body...

OBJECTIVE: The extant research on animal hoarding has a dearth of information on animal hoarding tendencies in adults diagnosed with hoarding disorder (HD). In the present study, we investigated possible recurrent animal hoarding behavioral and symptom patterns in individuals diagnosed with hoarding disorder. METHODS: Hoarding severity scores from baseline assessments for 65 community-dwelling adults diagnosed with HD were analyzed with respect to their present and past animal ownership characteristics...

Affective memories associated with the negative emotional state experienced during opiate withdrawal are central in maintaining drug-taking, seeking and relapse. Nucleus accumbens (NAC) is a key structure both for acute withdrawal and withdrawal memories reactivation, however NAC neuron coding properties underpinning the expression of these memories remain largely unknown. Here we aimed at deciphering the role of NAC neurons in the encoding and retrieval of opiate withdrawal memory. Chronic single neuron and local field potentials recordings were performed in morphine-dependent rats and placebo-controls...

Videos with rich social and emotional content elicit natural social behaviors in primates. Indeed, while watching videos of conspecifics, monkeys engage in eye contact, gaze follow, and reciprocate facial expressions. We hypothesized that the frequency and timing of eyeblinks also depends on the social signals contained in videos. We monitored the eyeblinks of four male adult macaques while they watched videos of conspecifics displaying facial expressions with direct or averted gaze. The instantaneous blink rate of all four animals decreased during videos...

Oxidative stress (OS) impact on a single neuron's function in vivo remains obscure. Using C. elegans as a model organism, we report the effect of paraquat (PQ)-induced OS on wild type worms on the function of the ASH polymodal neuron. By calcium (Ca(2+)) imaging, we quantified ASH activation upon stimulus delivery. PQ-treated worms displayed higher maximum depolarization (peak of the Ca(2+) transients) compared to untreated animals. PQ had a similar effect on the ASH neuron response time (rising slope of the Ca(2+) transients), except in very young worms...

Harvesting of wild-living animals is often intensive and may selectively target heritable behavioral traits. We studied the exploitation dynamics and the vulnerability consequences of individual heterogeneity in movement-related behaviors in free-ranging pearly razorfish (Xyrichthys novacula). Using underwater-video recording, we firstly document a fast and high exploitation rate of about 60% of the adult population removed in just few days after the opening of the season. Subsequently, we tagged a sample of individuals with acoustic transmitters and studied whether behavioral traits were significant predictors of the vulnerability to angling...